Aaaawww the bromance between Ned and Robert! A little underrated if you ask me. I guess because Robert could also behave like a huge asshole.
When Ned was eight years old he was sent to the Vale to be fostered by Jon Arryn. It was in the Vale that Ned met Robert Baratheon. Robert was also being fostered in the Vale, and the two boys became close friends for the rest of their lives. In fact, they became so attached to the Vale that when he turned sixteen, Ned spent his time going back and forth between the North and Vale.